Arterial stiffness is an independent predictor of cardiovascular morbidity and mortality. The aim was to investigate the relationship between dietary intake, metabolic profile and arterial stiffness in hypertensive patients.
Design and Method:
Dietary intake was self-reported using a 3 day diet record. Brachial blood pressure (BP) was measured using an oscillimetric technique (Omron) in the right arm. Using the same arm, augmentation index (AIx) and aortic BP were measured using radial applanation tonometry (SphygmoCor). Pulse wave velocity (PWV) was measured using the foot-to-foot method (Artech Medical). A fasting blood sample was collected for serum lipids and glucose determination, and bodyweight, height and waist circumference were measured.
Eighty adults (female, n = 40) with a mean ± sd age 49 ± 25y, body mass index (BMI) 29.7 ± 5.1 kg/m2 (n = 70) and waist circumference 101 ± 14 cm (n = 42) participated. PWV was 10.3 ± 2.4m/s (n = 36) and AIx was 27.1 ± 14.4% (n = 48). Dietary intake data was collected from n = 50 patients. Energy intake (EI) was 8.3 ± 3.9MJ/d, folate intake was 245 ± 105 μg/d and calcium intake was 751 ± 504 mg/d. The metabolic syndrome1 was present in 19/42 patients. AIx was inversely associated with bodyweight (r = -0.354, P < 0.05) and BMI (r = -0.289, P < 0.05). Dietary folate (r = -0.648, P < 0.01) and calcium (r = -0.539, P < 0.05) were inversely related to arterial stiffness as measured by AIx. Age and BP-adjusted correlation analysis showed EI was inversely associated with AIx (r = -0.477, P < 0.05). There were no significant associations between dietary intake of any macro- or micronutrients and PWV (P > 0.05).
These data suggest a paradoxical association between EI, bodyweight, BMI and arterial stiffness and may add further evidence to the ‘obesity paradox’. This relationship was not observed with PWV, suggesting the association is related to peripheral vascular resistance and wave reflections, rather than the speed of the forward pulse wave. The inverse association between AIx and both folate and calcium intake suggest these nutrients may have a beneficial effect on arterial compliance.